CN112838167A

CN112838167A - Display substrate and manufacturing method thereof

Info

Publication number: CN112838167A
Application number: CN201911162376.1A
Authority: CN
Inventors: 杨慧娟; 刘庭良; 尚庭华; 曹丹; 王予
Original assignee: BOE Technology Group Co Ltd; Chengdu BOE Optoelectronics Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Chengdu BOE Optoelectronics Technology Co Ltd
Priority date: 2019-11-22
Filing date: 2019-11-22
Publication date: 2021-05-25

Abstract

A display substrate and a method of manufacturing the same, the display device includes: a substrate base plate; the first conducting layer is arranged on the substrate and comprises first signal lines, second signal lines and an additional cushion layer which are arranged at intervals; the electroluminescent material layer is arranged on one side, far away from the substrate base plate, of the first conducting layer and comprises a first end portion and a second end portion, the first end portion is opposite to the second end portion, the orthographic projection of the first end portion on the substrate base plate falls into the orthographic projection of the first signal line on the substrate base plate, the orthographic projection of the second end portion on the substrate base plate falls into the orthographic projection of the additional cushion layer on the substrate base plate, and the orthographic projection of the first end portion on the substrate base plate and the orthographic projection of the second end portion on the substrate base plate are respectively located on two sides of the orthographic projection of the second signal line on the substrate base plate.

Description

Display substrate and manufacturing method thereof

Technical Field

The present disclosure relates to the field of display technologies, and in particular, to a display substrate and a method for manufacturing the same.

Background

An Organic Light-Emitting Diode (OLED) is a device that generates electroluminescence by using a multi-layer Organic thin film structure, and belongs to one type of electroluminescent devices, and is easy to manufacture and only requires a low driving voltage, and these main characteristics make the OLED very prominent in satisfying the application of flat panel displays. Compared with an LCD, the OLED display screen is thinner and lighter, has high brightness, low power consumption, quick response, high definition, good flexibility and high luminous efficiency, and can meet the new requirements of consumers on display technology.

Disclosure of Invention

Some embodiments of the present disclosure provide a display substrate, including: a substrate base plate; the first conducting layer is arranged on the substrate and comprises first signal lines, second signal lines and an additional cushion layer which are arranged at intervals; the electroluminescent material layer is arranged on one side, far away from the substrate base plate, of the first conducting layer and comprises a first end portion and a second end portion, the first end portion is opposite to the second end portion, the orthographic projection of the first end portion on the substrate base plate falls into the orthographic projection of the first signal line on the substrate base plate, the orthographic projection of the second end portion on the substrate base plate falls into the orthographic projection of the additional cushion layer on the substrate base plate, and the orthographic projection of the first end portion on the substrate base plate and the orthographic projection of the second end portion on the substrate base plate are respectively located on two sides of the orthographic projection of the second signal line on the substrate base plate.

In some embodiments, an orthographic projection of the electroluminescent material layer on the base substrate is an axisymmetric pattern symmetrical with respect to a center line of an orthographic projection of the second signal line on the base substrate, and an orthographic projection of the first end portion on the base substrate is symmetrical with an orthographic projection of the second end portion on the base substrate with respect to a center line of an orthographic projection of the second signal line on the base substrate.

In some embodiments, an orthographic projection of the first end portion on a first plane coincides with an orthographic projection of the second end portion on the first plane, wherein the first plane is perpendicular to the substrate base plate and parallel to a second signal line extending direction.

In some embodiments, the first signal line, the second signal line, and the additional pad layer are parallel to each other and a distance between the first signal line and the second signal line is equal to a distance between the second signal line and the additional pad layer.

In some embodiments, the electroluminescent material layer further comprises a first portion adjacent to the first end portion and a second portion adjacent to the second end portion, an orthographic projection of the first portion on the base substrate is between an orthographic projection of the first signal line on the base substrate and an orthographic projection of the second signal line on the base substrate, and an orthographic projection of the second portion on the base substrate is between an orthographic projection of the second signal line on the base substrate and an orthographic projection of the additional underlayer on the base substrate.

In some embodiments, an orthographic projection of the first portion on the substrate base plate and an orthographic projection of the second portion on the substrate base plate are symmetrical with respect to a center line of an orthographic projection of the second signal line on the substrate base plate.

In some embodiments, an orthographic projection of the first portion on a first plane coincides with an orthographic projection of the second portion on the first plane, wherein the first plane is perpendicular to the substrate base plate and parallel to a second signal line extending direction.

In some embodiments, the first end portion has a thickness equal to a thickness of the second end portion, the first portion has a thickness equal to a thickness of the second portion, and the first portion has a thickness greater than the thickness of the first end portion.

In some embodiments, the electroluminescent material layer further comprises a third portion located between the first portion and the second portion, an orthographic projection of the third portion on the substrate base plate falling within an orthographic projection of the second signal line on the substrate base plate.

In some embodiments, the third portion, the first end, and the second end are equal in thickness.

In some embodiments, the display substrate further comprises: the insulating layer is arranged on one side of the first conducting layer far away from the substrate base plate and is filled between the first signal line and the second signal line and between the second signal line and the additional cushion layer; and the first electrode is arranged on one side, far away from the substrate base plate, of the insulating layer, the electroluminescent material layer is arranged on one side, far away from the substrate base plate, of the first electrode, and the orthographic projection of the electroluminescent material layer on the substrate base plate falls into the orthographic projection of the first electrode on the substrate base plate.

In some embodiments, the insulating layer is provided with a first recess and a second recess on a side remote from the substrate base plate, a first portion of the electroluminescent material layer being provided partially in the first recess and a second portion of the electroluminescent layer being provided partially in the second recess.

In some embodiments, the display substrate further comprises: the orthographic projection of the first electrode on the substrate base plate is symmetrical to the midline of the orthographic projection of the second signal line on the substrate base plate, a first overlapping area exists between the orthographic projection of the first signal line on the substrate base plate and the orthographic projection of the first electrode on the substrate base plate, a second overlapping area exists between the orthographic projection of the additional cushion layer on the substrate base plate and the orthographic projection of the first electrode on the substrate base plate, and at least one part of the second overlapping area and the first overlapping area is symmetrical to the midline of the orthographic projection of the second signal line on the substrate base plate.

In some embodiments, the first conductive layer further includes a first electrical connection portion, an orthographic projection of the first electrical connection portion on the substrate base plate does not overlap with an orthographic projection of the first electrode on the substrate base plate, and the additional pad layer is electrically connected to the first electrical connection portion.

In some embodiments, the additional pad layer is in direct electrical contact with the first electrical connection.

In some embodiments, an orthographic projection of the additional pad layer on the substrate base plate falls within an orthographic projection of the first electrode on the substrate base plate, and the additional pad layer and the first electrical connection portion are electrically connected through a connection electrode.

In some embodiments, the first conductive layer comprises the connection electrode.

In some embodiments, the first conductive layer further includes a first signal terminal, an orthographic projection of the first signal terminal on the substrate base plate does not overlap with an orthographic projection of the first electrode on the substrate base plate, and the additional pad layer is electrically connected to the first signal terminal.

In some embodiments, the first signal line is a driving voltage power line, the second signal line is a data line, and the electroluminescent material layer is an electroluminescent material layer of a red electroluminescent device of the display substrate.

Some embodiments of the present disclosure provide a method of fabricating a display substrate, including: forming a first conductive layer on a substrate, wherein the first conductive layer includes a first signal line, a second signal line and an additional pad layer spaced from each other; the method comprises the steps of forming an electroluminescent material layer on a substrate base plate formed with a first conducting layer, wherein the electroluminescent material layer comprises a first end portion and a second end portion which are opposite, an orthographic projection of the first end portion on the substrate base plate falls into an orthographic projection of a first signal line on the substrate base plate, an orthographic projection of the second end portion on the substrate base plate falls into an orthographic projection of an additional cushion layer on the substrate base plate, and the orthographic projection of the first end portion on the substrate base plate and the orthographic projection of the second end portion on the substrate base plate are respectively located on two sides of an orthographic projection of the second signal line on the substrate base plate.

In some embodiments, prior to forming the layer of electroluminescent material, the method further comprises: forming an insulating layer over the substrate on which the first conductive layer is formed; and forming a first electrode on one side of the insulating layer far away from the substrate base plate, wherein the electroluminescent material layer is formed on one side of the first electrode far away from the substrate base plate.

Drawings

To more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be briefly described below, and it should be understood that the drawings described below relate only to some embodiments of the present disclosure, and not to limit the present disclosure, wherein:

FIG. 1 is a schematic view of a pixel arrangement of an OLED display substrate according to some embodiments of the present disclosure;

FIG. 2 is a circuit diagram of a drive circuit for one pixel of an OLED display substrate according to some embodiments of the present disclosure;

FIG. 3 is a schematic plan view of a red pixel region of an OLED display substrate according to some embodiments of the present disclosure;

FIG. 4 is a schematic cross-sectional view of the red pixel region of FIG. 3 taken along line A-A;

FIG. 5 is a schematic plan view of a red pixel region of an OLED display substrate according to some embodiments of the present disclosure;

FIG. 6 is a schematic cross-sectional view of the red pixel region of FIG. 5 taken along line A-A;

FIG. 7 is a schematic plan view of a red pixel region of an OLED display substrate according to some embodiments of the present disclosure;

FIG. 8 is a schematic cross-sectional view of the red pixel region of FIG. 7 taken along line A-A;

FIG. 9 is a schematic plan view of a red pixel region of an OLED display substrate according to some embodiments of the present disclosure;

fig. 10 is a schematic cross-sectional structure of the red pixel region of fig. 9 taken along line a-a;

FIG. 11 is a schematic plan view of a red pixel region of an OLED display substrate according to some embodiments of the present disclosure;

fig. 12 is a schematic cross-sectional structure of the red pixel region of fig. 11 taken along line a-a;

fig. 13 is a flow chart of a method of fabricating an OLED display substrate according to some embodiments of the present disclosure.

Detailed Description

To more clearly illustrate the objects, aspects and advantages of the present disclosure, embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. It is to be understood that the following description of the embodiments is intended to illustrate and explain the general concepts of the disclosure and should not be taken as limiting the disclosure. In the specification and drawings, the same or similar reference numerals refer to the same or similar parts or components. The figures are not necessarily to scale and certain well-known components and structures may be omitted from the figures for clarity.

Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather is used to distinguish one element from another. The word "a" or "an" does not exclude a plurality. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", "top" or "bottom", etc. are used merely to indicate relative positional relationships, which may change when the absolute position of the object being described changes. When an element such as a layer, film, region, or substrate is referred to as being "on" or "under" another element, it can be "directly on" or "under" the other element or intervening elements may be present.

Some of the present disclosure provide an electroluminescent display substrate, such as an OLED display substrate. The OLED display substrate in this embodiment includes a plurality of pixels, for example, red pixels, blue pixels, and green pixels. Fig. 1 illustrates a schematic pixel arrangement of an OLED display substrate according to some embodiments of the present disclosure. As shown in fig. 1, the pixels of the OLED display substrate in this embodiment are arranged in a GGRB manner, and the ratio of the number of red pixels to the number of blue pixels and the number of green pixels is 1: 2. The dashed line box in fig. 1 shows a cyclic unit of one pixel combination, which includes 1 red pixel R, 1 blue pixel B, and two green pixels G, i.e., a first green pixel G1 and a second green pixel G2. In this embodiment, the red pixel R and the blue pixel B are both hexamorphic, and the first green pixel G1 and the second green pixel G2 are pentagons symmetrical to each other. And the red pixel R, the blue pixel B, and the first green pixel G1 and the second green pixel G2 are all axisymmetric patterns. In other embodiments, the red pixel R, the blue pixel B, and the first and second green pixels G1 and G2 may also take other shapes.

In this embodiment, each pixel has one organic light emitting device (e.g., OLED) and one pixel driving circuit, and fig. 2 is a circuit diagram of a driving circuit of one pixel of an OLED display substrate according to some embodiments of the present disclosure. Referring to fig. 2, the pixel driving circuit has a 7T1C structure, that is, includes transistors T1, T2, T3, T4, T5, T6, T7, and a capacitor Cst, wherein the transistor T3 is a driving transistor. ELVDD denotes an ELVDD voltage applied by the power supply line, EM denotes an emission control signal from the emission control line, Data denotes a Data signal from the Data line, Gate denotes a scan signal from the Gate line, Reset denotes a Reset signal, which may be applied by the previous Gate line, Vinit denotes an initialization voltage, and ELVSS denotes an ELVSS voltage applied by the power supply line.

The gate of the transistor T3 is connected to the first capacitor plate Cstl of the capacitor Cst, for example, the gate of the transistor T3 and the first capacitor plate Cstl of the capacitor Cst are electrically connected to the first node N1. A source of the transistor T3 is connected to the ELVDD power supply line through the transistor T5. A drain of the transistor T3 is electrically connected to the organic light emitting device (e.g., OLED) through the transistor T6, e.g., a drain of the transistor T3 and the transistor T6 are electrically connected to the second node N2. The transistor T3 receives the Data signal Data according to the switching operation of the transistor T4 and supplies the driving current Id to the organic light emitting device.

The transistor T4 has a gate connected to the gate line, a source connected to the data line, and a drain connected to the source of the transistor T3 and to the ELVDD power supply line via the transistor T5. For example, the source of the transistor T3, the drain of the transistor T4, and the drain of the transistor T5 are electrically connected to the third junction N3.

The transistor T2 has a gate connected to the gate line, a source connected to the drain of the transistor T3 and connected to the organic light emitting device through the transistor T6, and a drain connected to the first capacitor plate Cstl of the capacitor Cst, the drain of the transistor T1, and the gate of the transistor T3. For example, the drain electrode of the transistor T2, the first capacitor plate Cstl of the capacitor Cst, the drain electrode of the transistor T1, and the gate electrode of the transistor T3 are electrically connected to the first node N1. The transistor T2 is turned on according to the scan signal Gate from the Gate line to electrically connect the Gate and the drain of the transistor T3, thereby placing the transistor T3 in a diode connected state.

The transistor T1 has a gate receiving a Reset signal Reset, a source receiving an initialization voltage Vinit, and a drain connected to the first node N1. The transistor T1 is turned on according to the Reset signal Reset to transmit the initialization voltage Vinit to the gate of the transistor T3.

The transistor T5 has a gate receiving the emission control signal EM, a source connected to the ELVDD power supply line, and a drain connected to the third node N3.

The transistor T6 has a gate receiving the emission control signal EM, a source connected to the second node N2, and a drain connected to the source of the transistor T7 and the organic light emitting device. For example, the drain electrode of the transistor T6, the source electrode of the transistor T7, and the organic light emitting device are electrically connected to the fourth node N4. The transistor T5 and the transistor T6 are simultaneously turned on according to the control signal EM from emission.

The transistor T7 has a Gate connected to the Gate line to receive the scan signal Gate, a source connected to the fourth node N4, and a drain receiving the initialization voltage Vinit.

The capacitor Cst further includes a second capacitor plate Cst2 connected to the ELVDD power supply line, and a first electrode (e.g., an anode) of the organic light emitting device is connected to the fourth node N4 and a second electrode (e.g., a cathode) is connected to the ELVSS power supply line. Accordingly, the organic light emitting device of the pixel may emit light based on the driving current from the transistor T3.

Fig. 3 illustrates a schematic plan view of a red pixel region of an OLED display substrate according to some embodiments of the present disclosure. Fig. 4 shows a schematic cross-sectional structure of the red pixel region of fig. 3 taken along line a-a. As shown in fig. 3 and 4, the red pixel region includes a substrate base plate 10 and a first conductive layer 11 disposed on the substrate base plate 10, the first conductive layer 11 includes a first signal line 111, such as a driving voltage power line (i.e., ELVDD power line), a second signal line 112, such as a data line, disposed at an interval from each other, a first electrical connection portion N1, such as a first node, and a first signal terminal 113, such as an initialization voltage terminal. The insulating layer 14 covers the first conductive layer 11, and since the components in the first conductive layer 11 are arranged at intervals, the surface of the insulating layer 14 on the side away from the substrate base plate 10 is not flat and appears uneven. The first electrode 13 of the red pixel, for example, an anode, is disposed on the side of the insulating layer 14 away from the substrate 10, and conforms to the surface shape of the side of the insulating layer 144 away from the substrate 10. The electroluminescent material layer 12 of the red pixel, for example, an organic luminescent material layer, is disposed on the side of the first electrode 13 away from the substrate 10, and the electroluminescent material layer 12 may be formed in a groove surrounded by the pixel defining layer 16. In fig. 3, the base substrate 10, the insulating layer 14, and the pixel defining layer 16 are omitted for clarity of illustrating the positional relationship of the respective components.

Referring to fig. 3 and 4, the orthographic projections of the first electrode 13 of the red pixel and the electroluminescent material layer 12 on the substrate 10 are symmetrical patterns taking the orthographic projection of the second signal line 112 on the substrate 10 as a symmetry axis, and are hexagonal. The orthographic projection of the electroluminescent material layer 12 of the red pixel on the base substrate 10 falls within the orthographic projection of the first electrode 13 of the electroluminescent material layer 12 of the red pixel on the base substrate 10. The orthographic projection of the first electrode 13 of the red pixel and the electroluminescent material layer 12 on the substrate base plate 10 and the orthographic projection of the first signal line 111 on the substrate base plate 10 have an overlapping area, and the orthographic projection of the first electrode 13 of the red pixel and the electroluminescent material layer 12 on the substrate base plate 10 and the orthographic projection of the second signal line 112 on the substrate base plate 10 have an overlapping area. There is no overlapping area between the orthographic projection of the first electrode 13 of the red pixel and the electroluminescent material layer 12 on the substrate 10 and the orthographic projection of the first node N1 on the substrate 10, and there is no overlapping area between the orthographic projection of the first electrode 13 of the red pixel and the electroluminescent material layer 12 on the substrate 10 and the orthographic projection of the first signal terminal 113 on the substrate 10.

The inventors found that the red pixels of the OLED display substrates in fig. 3 and 4 had color shift. The inventors consider that the reason for this color shift is as follows: as shown in fig. 3 and 4, the left edge region of the electroluminescent material layer 12 of the red pixel has an overlapping region with the first conductive layer 11 (the first signal line 111), and the left edge region of the electroluminescent material layer 12 has no overlapping region with the first conductive layer 11, so that the left and right edge regions of the electroluminescent material layer 12 have different thicknesses, and thus, the red pixel emits light with color difference.

In order to overcome the above problems, some embodiments of the present disclosure provide a display substrate, including: a substrate base plate; the first conducting layer is arranged on the substrate and comprises first signal lines, second signal lines and an additional cushion layer which are arranged at intervals; the electroluminescent material layer is arranged on one side, far away from the substrate base plate, of the first conducting layer and comprises a first end portion and a second end portion which are opposite, the orthographic projection of the first end portion on the substrate base plate falls into the orthographic projection of the first signal line on the substrate base plate, the orthographic projection of the second end portion on the substrate base plate falls into the orthographic projection of the additional cushion layer on the substrate base plate, and the orthographic projection of the first end portion on the substrate base plate and the orthographic projection of the second end portion on the substrate base plate are respectively located on two sides of the orthographic projection of the second signal line on the substrate base plate. In the present disclosure, by providing the additional pad layer disposed on the same layer as the first signal line, the additional pad layer pads up the right edge region of a pixel, for example, a red pixel, and the left edge region and the right edge region of the pixel are substantially symmetrical in structure, at this time, the left edge region and the right edge region of the electroluminescent material layer of the red pixel have the same thickness and are substantially located at the same height, so that the left edge region and the right edge region of the red pixel emit light substantially uniformly, and color shift is reduced.

Fig. 5 illustrates a schematic plan view of a red pixel region of an OLED display substrate according to some embodiments of the present disclosure. Fig. 6 shows a schematic cross-sectional structure of the red pixel region of fig. 5 taken along line a-a. As shown in fig. 5 and 6, the red pixel region includes a substrate 10 and a first conductive layer 11 disposed on the substrate 10, the first conductive layer 11 includes a first signal line 111 (e.g., an ELVDD power line, which is described as an ELVDD power line in the following embodiments and may also be referred to as the ELVDD power line 111), a second signal line 112 (e.g., a data line, which is described as a data line in the following embodiments and may also be referred to as the data line 112), a first electrical connection portion N1 (e.g., a first node, which is described as a first node in the following embodiments and may also be referred to as a first node N1), and a first signal terminal 113 (e.g., an initialization voltage terminal, which is described as an initialization voltage terminal in the following embodiments and may also be referred to as the initialization voltage terminal 113). In addition, the first conductive layer 11 further includes an additional pad layer 17, and the additional pad layer 17 may be disposed in the same layer as the first signal line 111, the second signal line 112, the first electrical connection portion N1, and the first signal terminal 113, and may be formed using the same material and the same patterning process, for example. The first conductive layer 11 is generally disposed on a flat surface, and thus, the surfaces of the first signal line 111, the second signal line 112, the first electrical connection portion N1, the first signal terminal 113, and the additional pad layer 17 close to the substrate base 10 are all equidistant from the substrate base 10, and they have the same thickness.

In some embodiments, the red pixel region further includes another layer structure 15, such as a gate layer, an active layer, a planarization layer, etc., disposed between the substrate 10 and the first conductive layer 11, and a surface of the other layer structure 15 contacting the first conductive layer 11 is generally flat to facilitate formation of the first conductive layer 11.

As shown in fig. 5 and 6, the insulating layer 14 covers the first conductive layer 11. The first electrode 13 (for example, an anode, which is described as an example in the following embodiments and may be referred to as the anode 13 hereinafter) of the red pixel is disposed on the side of the insulating layer 14 away from the substrate 10 and conforms to the surface shape of the insulating layer 14 away from the substrate 10. The electroluminescent material layer 12 of the red pixel, for example, an organic luminescent material layer, is disposed on a side of the first electrode 13 away from the substrate 10, and the electroluminescent material layer 12 may be formed in a groove surrounded by the pixel defining layer 16, and may include a hole injection layer, a hole transport layer, a luminescent layer, an electron transport layer, and an electron injection layer stacked in sequence away from the substrate. In fig. 5, the base substrate 10, the insulating layer 14, and the pixel defining layer 16 are omitted for clarity of illustrating the positional relationship of the respective components.

Referring to fig. 5 and 6, the electroluminescent material layer 12 includes a first end portion 121 and a second end portion 122 disposed opposite to each other and respectively located at the left and right ends of the electroluminescent material layer 12. The orthographic projection of the first end portion 121 on the substrate base 10 falls within the orthographic projection of the ELVDD power supply line 111 on the substrate base 10. That is, there is an overlapping region where the orthographic projection of the electroluminescent material layer 12 on the base substrate 10 and the orthographic projection of the ELVDD power supply line 111 on the base substrate 10 fall or coincide with the overlapping region. The orthographic projection of the second end portion 122 on the substrate base plate 10 falls within the orthographic projection of the additional cushion layer 17 on the substrate base plate 10. That is, there is an overlapping region between the orthographic projection of the electroluminescent material layer 12 on the base substrate 10 and the orthographic projection of the additional pad layer 117 on the base substrate 10, and the orthographic projection of the second end portion 122 on the base substrate 10 falls within or coincides with the overlapping region. By providing the additional pad layer on the same layer as the first signal line, the additional pad layer pads up the right edge region of the red pixel to compensate for the color difference caused by the difference in thickness between the left and right edge regions of the electroluminescent material layer 12 in the embodiments shown in fig. 3 and 4.

In some embodiments, referring to fig. 5 and 6, the orthographic projection of the electroluminescent material layer 12 on the substrate 10 is a symmetrical pattern, such as a hexagon, with the central line of the orthographic projection of the data line 112 on the substrate 10 as the symmetry axis. In the present disclosure, the orthographic projection of the data line 12 on the base substrate 10 is in a long shape, and the central line of the orthographic projection of the data line 12 on the base substrate 10 extends along the direction in which the data line 12 extends. The orthographic projection of the first end part 121 of the electroluminescent material layer 12 on the substrate base plate 10 and the orthographic projection of the second end part 122 on the substrate base plate 10 are symmetrical relative to the midline of the orthographic projection of the data line 12 on the substrate base plate 10. The shape and area of the orthographic projection of the first end portion 121 on the substrate 10 are substantially the same as those of the orthographic projection of the second end portion 121 on the substrate 10. Therefore, the right edge region of the red pixel electroluminescent material layer 12 padded by the additional pad layer has substantially the same area and shape as the left edge region padded by the ELVDD power supply line 111, which is advantageous for reducing edge color difference.

In some embodiments, referring to fig. 5 and 6, an orthographic projection of the first end portion 121 on a first plane M perpendicular to the substrate base plate 10 and parallel to the extending direction of the data line 112 coincides with an orthographic projection of the second end portion 122 on the first plane M, and the first plane M may be a central line including the orthographic projection of the data line 112 on the substrate base plate 10, that is, a central line of the orthographic projection of the data line 112 on the substrate base plate 10 may be located on the first plane M. The distance between the surface of the first end portion 121 of the electroluminescent material layer 12 of the red pixel facing the base substrate 10 and the base substrate 10 is substantially equal to the distance between the surface of the second end portion 122 facing the base substrate 10 and the base substrate 10, and the first end portion 121 and the second end portion 122 have the same thickness, both being the first thickness d 1. It is understood that the first end 121 and the second end 122 are at the same height and have the same thickness. The first end 121 and the second end 122 of the electroluminescent material layer 12 are substantially symmetrical with respect to the first plane M. At this time, the right edge region of the electroluminescent material layer 12 of the red pixel, which is padded by the additional padding, is at the same height and has the same thickness as the left edge region, which is padded by the ELVDD power line 111, which is beneficial to reducing the edge color difference.

In some embodiments, as shown in fig. 5 and 6, the additional pad layer 17 is disposed apart from the ELVDD power line 111, the data line 112, the first node N1, and the first signal terminal 113. Specifically, the ELVDD power line 111, the data line 112, and the additional pad layer 17 are parallel to each other and sequentially disposed at equal intervals. I.e., the distance between the ELVDD power line 111 and the data line 112 is equal to the distance between the data line 112 and the additional pad layer 17.

In some embodiments, as shown in fig. 5 and 6, since the first conductive layer 11 is generally disposed on a flat surface, and there are spaces between the ELVDD power line 111 and the data line 112 in the first conductive layer 11 and between the data line 112 and the additional pad layer 17, the surface of the subsequently formed insulating layer 14 covering the first conductive layer 11, which is far from the substrate base plate 10, is not flat, and the insulating layer 14 is provided with a first recess 141 and a second recess 142 on the side far from the substrate base plate. Wherein an orthogonal projection of the first recess 141 on the substrate base 10 is located between an orthogonal projection of the ELVDD power line 111 on the substrate base 10 and an orthogonal projection of the data line 112 on the substrate base 10. The orthographic projection of the second recess 142 on the substrate base plate 10 is located between the orthographic projection of the additional pad layer 17 on the substrate base plate 10 and the orthographic projection of the data line 112 on the substrate base plate 10. The anode 13 disposed on the side of the insulating layer 14 remote from the base substrate 10 conforms to the surface shape of the insulating layer 14 remote from the base substrate 10.

In some embodiments, as shown in fig. 5 and 6, the electroluminescent material layer 12 further includes a first portion 123 adjacent the first end 121 and a second portion 124 adjacent the second end 122. The first portion 123 of the electroluminescent material layer 12 is located partly in the first recess 141 and the second portion 124 is located partly in the second recess 142. The orthographic projection of the first portion 123 on the base substrate 10 is located between the orthographic projection of the ELVDD power line 111 on the base substrate 10 and the orthographic projection of the data line 112 on the base substrate 10. That is, there is no overlap between the orthographic projection of the first portion 123 on the base substrate 10 and the orthographic projection of the ELVDD power line 111 on the base substrate 10 and the orthographic projection of the data line 112 on the base substrate 10. The orthographic projection of the second portion 124 on the substrate base 10 is located between the orthographic projection of the additional pad layer 17 on the substrate base 10 and the orthographic projection of the data line 112 on the substrate base 10. Namely, there is no overlap between the orthographic projection of the second portion 124 on the substrate base plate 10, the orthographic projection of the additional pad layer 17 on the substrate base plate 10 and the orthographic projection of the data line 112 on the substrate base plate 10.

With continued reference to fig. 5 and 6, the orthographic projection of the first portion 123 on the substrate base 10 and the orthographic projection of the second portion 124 on the substrate base 10 are substantially symmetrical with respect to a center line of the orthographic projection of the data line 10 on the substrate base 10, and the orthographic projection of the first portion 123 on the first plane M coincides with the orthographic projection of the second portion 124 on the first plane M, i.e. the first portion 123 and the second portion 124 of the electroluminescent material layer 12 are substantially symmetrical with respect to the first plane M. The distance between the surface of the first portion 123 of the layer 12 of electroluminescent material facing the base substrate 10 and the base substrate 10 is substantially equal to the distance between the surface of the second portion 122 facing the base substrate 10 and the base substrate 10, and the first portion 123 and the second portion 124 are of the same thickness, both being the second thickness d 2. It is understood that the first portion 123 and the second portion 124 are at the same height and have the same thickness. The second thickness d2 is greater than the first thickness d1 due to the interval between the ELVDD power line 111 and the data line 112 and the interval between the data line 112 and the additional pad layer 17.

With continued reference to fig. 5 and 6, the layer of electroluminescent material 12 also includes a third portion 125 located between the first portion 123 and the second portion 124. The orthographic projection of the third portion 125 on the substrate base 10 is located within the orthographic projection of the data line 112 on the substrate base 10. The thickness of the third portion 125 is substantially the same as the thickness of the first end portion 121 and the second end portion 122, both being the first thickness d 1. Accordingly, the electroluminescent material layer 12 is substantially symmetrical with respect to the first plane M as a whole, so that the left area and the right area of the red pixel emit light substantially uniformly, reducing color shift.

In some embodiments, as shown in fig. 5 and 6, the orthographic projection of the anode 13 of the red pixel on the substrate base 10 is symmetrical, for example, hexagonal, with respect to the central line of the orthographic projection of the data line 112 on the substrate base 10. The orthographic projection of the ELVDD power line 111 on the substrate base plate 10 and the orthographic projection of the anode 13 on the substrate base plate 10 have a first overlapping area, the orthographic projection of the additional pad layer 17 on the substrate base plate 10 and the orthographic projection of the anode 13 on the substrate base plate 10 have a second overlapping area, and at least one part of the second overlapping area and the first overlapping area are symmetrical relative to the central line of the orthographic projection of the data line 112 on the substrate base plate 10. The orthographic projection of the first end portion 121 of the electroluminescent material layer 12 of the red pixel on the base substrate 10 falls within the first overlap region, and the orthographic projection of the second end portion 122 on the base substrate 10 falls within the second overlap region. Therefore, the first end portion 121 and the second end portion 122 of the electroluminescent material layer 12 are affected by the voltage applied from the anode 13 to be substantially uniform at the left and right end portions of the red pixel, so that the light emitting effect at the left and right end portions of the red pixel is substantially uniform, and the color difference is reduced.

In some embodiments, as shown in fig. 5 and 6, the orthographic projection of the additional pad layer 17 on the substrate base plate 10 falls within the orthographic projection of the anode 13 on the substrate base plate 10, and the orthographic projection of the first node N1 on the substrate base plate 10 does not overlap with the orthographic projection of the anode 13 on the substrate base plate 10. The orthographic projection of the first signal terminal 113 on the substrate base 10 and the orthographic projection of the anode 13 on the substrate base 10 do not overlap. At this time, the additional pad layer 17 is insulated from the first node N1 and the first signal terminal 113.

Fig. 7 illustrates a schematic plan view of a red pixel region of an OLED display substrate according to some embodiments of the present disclosure. Fig. 8 shows a schematic cross-sectional structure of the red pixel region of fig. 7 taken along the line a-a. In these embodiments, the structure of the red pixel region of the OLED display substrate is substantially the same as that of the OLED display substrate in the corresponding embodiments of fig. 5 and 6. The difference between the two will be mainly described below.

As shown in fig. 7 and 8, the additional pad layer 17' is directly electrically connected to the first node N1. Although fig. 7 and 8 show the boundary between the additional pad 17 ' and the first node N1, it can be understood by those skilled in the art that the additional pad 17 ' is integrally connected to the first node N1, and the additional pad 17 ' can be considered as extending from the first node N1 toward the data line 112. In this embodiment, the orthographic projection of the additional pad layer 17' on the substrate base plate 10 does not fall into the orthographic projection of the anode 13 on the substrate base plate 10, but has an overlapping region with the orthographic projection of the anode 13 on the substrate base plate 10. The structure of the additional pad layer 17' directly electrically connected to the first node N1 has a simple process and is easy to manufacture. And because the additional pad layer 17 'is directly and electrically connected with the first node N1, the adverse effect of static electricity accumulated on the display substrate due to the formation of an isolated island of the additional pad layer 17' can be avoided.

Fig. 9 illustrates a schematic plan view of a red pixel region of an OLED display substrate according to some embodiments of the present disclosure. Fig. 10 shows a schematic cross-sectional structure of the red pixel region of fig. 9 taken along the line a-a. In these embodiments, the structure of the red pixel region of the OLED display substrate is substantially the same as that of the OLED display substrate in the corresponding embodiments of fig. 5 and 6. The difference between the two will be mainly described below.

As shown in fig. 9 and 10, the additional pad layer 17 ″ is electrically connected to the first node N1 through the connection electrode 18. For example, one end of the connection electrode 18 may be electrically connected to one end of the first node N1, for example, the lower end shown in fig. 10, and the other end of the connection electrode 18 may be electrically connected to one end of the additional pad layer 17 ", for example, the lower end shown in fig. 10. In other embodiments, the connecting electrode 18 may be connected to other regions of the first node N1, and may also be connected to other regions of the additional pad layer 17 ″.

In some embodiments, the connection electrode 18 may be disposed in the same layer as the additional pad layer 17 ″ and the first node N1, i.e., the connection electrode 18 may also be a part of the first conductive layer 11. This arrangement allows the connection electrode 18 to be formed by the same patterning process as the additional pad layer 17 ″ and the first node N1, and for example, the connection electrode 18 may be formed integrally with the additional pad layer 17 ″ and the first node N1, thereby reducing the manufacturing cost. In some embodiments, the connection electrode 18 may be located in a different layer from the additional pad 17 "and the first node N1, as long as the connection electrode 18 is ensured to enable an electrical connection between the additional pad 17" and the first node N1. And because the additional pad layer 17 ″ is electrically connected with the first node N1, the influence of static electricity accumulated on the display substrate due to the formation of an isolated island of the additional pad layer 17' can be avoided.

Fig. 11 illustrates a schematic plan view of a red pixel region of an OLED display substrate according to some embodiments of the present disclosure. Fig. 12 shows a schematic cross-sectional structure of the red pixel region of fig. 11 taken along the line a-a. In these embodiments, the structure of the red pixel region of the OLED display substrate is substantially the same as that of the OLED display substrate in the corresponding embodiments of fig. 5 and 6. The difference between the two will be mainly described below.

As shown in fig. 11 and 12, the additional pad 17 'is electrically connected to the first signal terminal 113, e.g., the additional pad 17' "is in direct electrical contact with the first signal terminal 113. Although the boundary between the additional pad 17 ' "and the first signal terminal 113 is shown in fig. 11 and 12, it will be understood by those skilled in the art that the additional pad 17 '" is integrally connected to the first signal terminal 113, and the additional pad 17 ' "can be considered as extending from the first signal terminal 113 towards the data line 112. In this embodiment, the orthographic projection of the additional cushion layer 17' ″ on the substrate base plate 10 does not fall into the orthographic projection of the anode 13 on the substrate base plate 10, but has an overlapping region with the orthographic projection of the anode 13 on the substrate base plate 10. The structure that the additional cushion layer 17' ″ is directly and electrically connected with the first signal terminal 113 is simple in process and easy to manufacture. And because the additional cushion layer 17 '″ is directly and electrically connected with the first signal terminal 113, the adverse effect of static electricity accumulated on the display substrate caused by the formation of an isolated island of the additional cushion layer 17' ″ can be avoided.

In other embodiments, the additional pad layer 17 '"may also be electrically connected to the first signal terminal 113 through a connection electrode, and the connection electrode may be disposed on the same layer as the additional pad layer 17'" and the first signal terminal 113, or may be disposed on different layers.

The foregoing embodiments of the present disclosure have been substantially described with respect to red pixel regions of an OLED display substrate. It will be understood by those skilled in the art that for pixel regions of other colors, the color shift problem caused by the structure similar to that in the corresponding embodiments of fig. 3 and 4 can also be solved by the solution in the foregoing embodiments.

Some embodiments of the present disclosure provide a display device, which may include the display substrate in the foregoing embodiments. The display device may be: the mobile phone comprises any product or component with a display function and a camera shooting function, such as a television, a display, a digital photo frame, a mobile phone, an intelligent watch, a tablet personal computer and the like.

Some embodiments of the present disclosure provide a method of manufacturing a display substrate, and fig. 13 illustrates a flowchart of the method of manufacturing a display substrate according to some embodiments of the present disclosure. As shown in fig. 13, the method for manufacturing a display substrate includes the steps of:

s10: a first conductive layer is formed on a substrate, wherein the first conductive layer includes a first signal line, a second signal line and an additional pad layer spaced apart from each other.

S40: an electroluminescent material layer is formed on the base substrate on which the first conductive layer is formed.

Specifically, in some embodiments, in step S10, a first conductive material layer may be deposited on the substrate, and patterned by a single patterning process to form a first conductive layer including a first signal line, a second signal line and an additional pad layer, which are spaced apart from each other.

Specifically, in some embodiments, in step S20, a pixel defining material layer may be coated on the substrate on which the first conductive layer is formed, a partial region of the pixel defining material layer is removed through a patterning process to form a pixel defining layer and a groove surrounded by the pixel defining layer, and the electroluminescent material is filled into the groove layer to form an electroluminescent material layer.

The structure of the red pixel region of the OLED display substrate shown in fig. 5 may be formed based on the above-described method. In the structure formed by the method, the electroluminescent material layer includes a first end and a second end which are opposite, an orthographic projection of the first end on the substrate falls into an orthographic projection of the first signal line on the substrate, an orthographic projection of the second end on the substrate falls into an orthographic projection of the additional cushion layer on the substrate, and the orthographic projection of the first end on the substrate and the orthographic projection of the second end on the substrate are respectively located on two sides of an orthographic projection of the second signal line on the substrate. The additional cushion layer arranged on the same layer as the first signal line is arranged, so that the additional cushion layer cushions the right side edge area of a pixel, such as a red pixel, and the structure of the left side edge area and the right side edge area of the pixel is basically symmetrical, at the moment, the thickness of the left side edge area and the thickness of the right side edge area of the electroluminescent material layer of the red pixel are the same and are basically symmetrical, so that the left side edge area and the right side edge area of the red pixel emit light basically in the same direction, and color cast is reduced.

In some embodiments, before forming the electroluminescent material layer, as shown in fig. 13, the method for manufacturing a display substrate further includes the steps of:

s20: forming an insulating layer over the substrate on which the first conductive layer is formed;

s30: and forming a first electrode on one side of the insulating layer far away from the substrate.

In step S20, an insulating layer may be formed by a deposition process, covering the first conductive layer including the first signal line, the second signal line and the additional pad layer spaced apart from each other, and filling between adjacent two of the first signal line, the second signal line and the additional pad layer.

In step S30, a first electrode may be formed using a patterning process, the first electrode being formed on and conforming to a shape of a surface of the insulating layer remote from the base substrate.

Although the present disclosure is described in connection with the accompanying drawings, the embodiments disclosed in the drawings are intended to be illustrative of the embodiments of the disclosure, and should not be construed as a limitation of the disclosure. The dimensional proportions in the drawings are merely schematic and are not to be understood as limiting the disclosure.

The foregoing embodiments are merely illustrative of the principles and configurations of this disclosure and are not to be construed as limiting thereof, it being understood by those skilled in the art that any variations and modifications of the disclosure may be made without departing from the general concept of the disclosure. The protection scope of the present disclosure shall be subject to the scope defined by the claims of the present application.

Claims

1. A display substrate, comprising:

a substrate base plate;

the first conducting layer is arranged on the substrate and comprises first signal lines, second signal lines and an additional cushion layer which are arranged at intervals;

an electroluminescent material layer arranged on one side of the first conductive layer far away from the substrate base plate,

the electroluminescent material layer comprises a first end part and a second end part which are opposite, the orthographic projection of the first end part on the substrate base plate falls into the orthographic projection of the first signal line on the substrate base plate, the orthographic projection of the second end part on the substrate base plate falls into the orthographic projection of the additional cushion layer on the substrate base plate, and the orthographic projection of the first end part on the substrate base plate and the orthographic projection of the second end part on the substrate base plate are respectively positioned on two sides of the orthographic projection of the second signal line on the substrate base plate.

2. The display substrate according to claim 1, wherein an orthographic projection of the electroluminescent material layer on the substrate is an axisymmetric pattern with respect to a center line of an orthographic projection of the second signal line on the substrate, and an orthographic projection of the first end portion on the substrate and an orthographic projection of the second end portion on the substrate are symmetric with respect to a center line of an orthographic projection of the second signal line on the substrate.

3. The display substrate according to claim 2, wherein an orthographic projection of the first end portion on a first plane is coincident with an orthographic projection of the second end portion on a first plane, wherein the first plane is perpendicular to the substrate base plate and parallel to a second signal line extending direction.

4. The display substrate of claim 3, wherein the first signal line, the second signal line, and the additional pad layer are parallel to each other and a distance between the first signal line and the second signal line is equal to a distance between the second signal line and the additional pad layer.

5. The display substrate of claim 4, wherein the electroluminescent material layer further comprises a first portion adjacent to the first end and a second portion adjacent to the second end, an orthographic projection of the first portion on the substrate being between an orthographic projection of the first signal line on the substrate and an orthographic projection of the second signal line on the substrate, and an orthographic projection of the second portion on the substrate being between an orthographic projection of the second signal line on the substrate and an orthographic projection of the additional underlayer on the substrate.

6. The display substrate according to claim 5, wherein an orthogonal projection of the first portion on the substrate and an orthogonal projection of the second portion on the substrate are symmetrical with respect to a center line of an orthogonal projection of the second signal line on the substrate.

7. A display substrate according to claim 5, wherein an orthographic projection of the first portion on a first plane, perpendicular to the substrate base plate and parallel to the second signal line extension direction, coincides with an orthographic projection of the second portion on a first plane.

8. The display substrate of claim 5, wherein a thickness of the first end portion is equal to a thickness of the second end portion, a thickness of the first portion is equal to a thickness of the second portion, and the thickness of the first portion is greater than the thickness of the first end portion.

9. A display substrate according to claim 5, wherein the layer of electroluminescent material further comprises a third portion located between the first and second portions, an orthographic projection of the third portion on the substrate lying within an orthographic projection of the second signal line on the substrate.

10. The display substrate of claim 9, wherein the third portion, the first end portion, and the second end portion are equal in thickness.

11. The display substrate of claim 5, further comprising:

the insulating layer is arranged on one side of the first conducting layer far away from the substrate base plate and is filled between the first signal line and the second signal line and between the second signal line and the additional cushion layer; and

a first electrode disposed on a side of the insulating layer away from the substrate base,

the electroluminescent material layer is arranged on one side of the first electrode, which is far away from the substrate base plate, and the orthographic projection of the electroluminescent material layer on the substrate base plate falls into the orthographic projection of the first electrode on the substrate base plate.

12. A display substrate according to claim 11, wherein the insulating layer is provided with a first recess and a second recess on a side remote from the substrate base, a first part of the electroluminescent material layer being provided partly in the first recess and a second part of the electroluminescent layer being provided partly in the second recess.

13. The display substrate of claim 11, further comprising: the orthographic projection of the first electrode on the substrate base plate is symmetrical to the midline of the orthographic projection of the second signal line on the substrate base plate, a first overlapping area exists between the orthographic projection of the first signal line on the substrate base plate and the orthographic projection of the first electrode on the substrate base plate, a second overlapping area exists between the orthographic projection of the additional cushion layer on the substrate base plate and the orthographic projection of the first electrode on the substrate base plate, and at least one part of the second overlapping area and the first overlapping area is symmetrical to the midline of the orthographic projection of the second signal line on the substrate base plate.

14. The display substrate according to claim 11, wherein the first conductive layer further comprises a first electrical connection portion, an orthographic projection of the first electrical connection portion on the substrate does not overlap with an orthographic projection of the first electrode on the substrate, and the additional pad layer is electrically connected to the first electrical connection portion.

15. The display substrate of claim 14, wherein the additional pad layer is in direct electrical contact with the first electrical connection.

16. The display substrate according to claim 14, wherein an orthographic projection of the additional pad layer on the substrate falls within an orthographic projection of the first electrode on the substrate, the additional pad layer being electrically connected to the first electrical connection portion through a connection electrode.

17. The display substrate of claim 16, wherein the first conductive layer comprises the connection electrode.

18. The display substrate of claim 11, wherein the first conductive layer further comprises a first signal terminal, an orthographic projection of the first signal terminal on the substrate does not overlap with an orthographic projection of the first electrode on the substrate, and the additional pad layer is electrically connected to the first signal terminal.

19. The display substrate according to any one of claims 1 to 18, wherein the first signal line is a driving voltage supply line, the second signal line is a data line, and the electroluminescent material layer is an electroluminescent material layer of a red electroluminescent device of the display substrate.

20. A method of making a display substrate, comprising:

forming a first conductive layer on a substrate, wherein the first conductive layer includes a first signal line, a second signal line and an additional pad layer spaced from each other;

forming an electroluminescent material layer on the base substrate on which the first conductive layer is formed,

21. The method of claim 20, further comprising, prior to forming the layer of electroluminescent material:

forming an insulating layer over the substrate on which the first conductive layer is formed; and

forming a first electrode on one side of the insulating layer far away from the substrate base plate,

wherein the electroluminescent material layer is formed on the side of the first electrode away from the substrate base plate.